“laser guided inspection robot for the non destructive testing in the

Copyright © TWI Ltd 2014

6th October 2014

“Laser guided inspection robot for the Non Destructive Testing in the shipping industry”

TWI Ltd

Cambridge, Cambridgeshire, CB21 6AL, UK

www.x-scan.eu [email protected]

ECNDT 2014

http://www.x-scan.eu/



mailto:[email protected]


Background

Structural failure is a major cause of the loss of ships, resulting in loss of life and pollution of Europe waters

The European Union accounts for 27 % of this traffic, with 90 % of Europe’s oil arriving by sea

Tanker accidents account for 12% of all oil pollution

Each year over 400 ocean going ships sink, many as a result of weakened structures (corrosion, welding quality)

Europe owns 40% of the world’s fleet of ships, which account for 90% of its external and 40% of its internal trade


Industrial Need

Technological problem MPI is the most common technique used for surface

defects

It needs a manual operator to apply the chemicals and visually check

Electromagnetic techniques like ACFM can remote access

Radiography is the mainstay technique used for volumetric defects

Dangerous radiation, needs special permission, also no other work is allowed at the same time

PAUT can provide a sustitude


Industrial Need

Technological problem (cont.) The inspection also involves

Scaffolding, cherry-pickers, rope access

Existing semi-automated inspection robot Basic UT methods to perform thickness measurements Manual identification of the weld prior to deployment\

Industrial need Need for solution to gradually replace the use of

radiography for the on-site inspection in the shipping industry


X-Scan Project Concept

Concept To combine advanced ultrasonic and electromagnetic

techniques to fully inspect plate welds in one complete unit capable of guiding itself

The following technologies were developed A wall climbing robot A laser based seam tracking subsystem Phased Array probe(s), methodology and technology ACFM array probe(s), methodology and technology


Automation of weld inspection

Robot specifications:

Wall climbing capability

Weld seam automatic following

Carry all needed equipment: Control unit, motors,

pneumatics and irrigation Laser profile meter NDT holder and probes PAUT unit and splitter ACFM splitter Encoder splitter Cabling and accessories


Laser profile meter seam tracking

Laser profile meter arrangement: Butt weld (top left)

Fillet weld (bottom right)

Tests on a coated butt weld

using an x-y scanner (right)

Curve fitting and threshold algorithms for both arrangements


Laser profile meter seam tracking

Software interface of the seam tracker, not needed in automatic mode


PAUT system

• Olympus Omniscan MX – Proven system, VNC operation

• Custom built probes after simulation – Linear, 32 el, 7MHz

• Rexolite wedge • Water cavity wedge tested


PAUT inspection

Inspection technique applied: Solid wedge / water wedge Encoded manual scan with string encoder (step size 1mm) Sector scan using 32 elements from 30° to 75° (angular step

0.5°) Focus in projection along the weld centreline


ACFM array system


ACFM array system

Probes and Splitter Box used for ACFM measurements


ACFM inspection


Probe holder

Butt weld configuration


Probe holder

Fillet weld configuration


Integration tests

3x3m 0.5ton custom build plate for testing

Butt weld scan (top) Fillet weld scan (right)


Integration Video Butt


Integration Video Fillet


Demo

4 meters up on the hull of a dry dock and going, rope for safety only


Demo Video


ACFM results


PAUT results


Conclusions

Different inspection techniques focussing on

different parts of the weld Combination of all techniques enable the

whole coverage of the weld Scanning speeds of 30mm/sec achieved Results better for thicker than thinner plates Accurate positioning issues


Future work

Further funding being sought for :

Miniaturizing Smaller UT array controller ACFM weld contour array probe Splitters (4 on board) and accessory electronics,

bottom up redesigned to fit Separation of fillet and butt configurations

Holder simplification Marinising


Contact

Name Giorgos Asfis Integrity Management Group TWI Ltd Tel: +44 (0)1223 899 000 E-mail: [email protected] Web: www.twi-global.com

mailto:[email protected]

http://www.twi-global.com/




Copyright

Presentation prepared for ECNDT by TWI under Project No. 21493

TWI holds copyright on this presentation.

All rights reserved. No part of this presentation may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without

the express permission of TWI.

“laser guided inspection robot for the non destructive testing in the

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